Invasive pneumococcal disease in a tertiary hospital in Madrid: are we using pneumococcal vaccine correctly?

Abstract

Introduction

Invasive pneumococcal disease (IPD) is of concern. We describe the epidemiology and assess the vaccination schedule adequacy of IPD episodes (2019–2021) in northern Madrid.

Methods

Clinical, laboratory and vaccination data were collected from clinical/epidemiological records. Antimicrobial susceptibility testing was performed according to EUCAST and serotyping by Pneumotest-agglutination/Quellung.

Results

IPD was identified in 103 patients (71 [IQR 23.5] year-old; 50.4% males), 85.4% associated with bacteremia and a high mortality rate (19.4%). Serotypes 8 (29.9%), 3 and 22F (8% each) were dominant (45.9%), all antibiotic-susceptible. β-Lactams increased MICs and macrolide resistance were mainly linked to serotypes 19A, 23F, 24F, 6C, and 15A. Only 10.5% of adults eligible for vaccination had an adequate vaccine regimen before IPD being 40% due to nonvaccine-preventable serotypes (13, 23B, 24F, 31).

Conclusion

IPD episodes were dominated by antibiotic-susceptible ST8 and frequently occurred in adults at risk. Despite recommendations, vaccination adherence rates were very low.

Resumen

Introducción

Describimos la epidemiología y evaluamos la adecuación de la vacunación de los episodios de la enfermedad neumocócica invasiva (ENI) (2019-2021) en el norte de Madrid.

Métodos

Los datos se obtuvieron de registros clínicos/epidemiológicos, las pruebas de sensibilidad se realizaron mediante criterios EUCAST y el serotipado mediante Pneumotest/Quellung.

Resultados

Se detectaron 103 casos en varones (50,4%) asociados a bacteriemia (85,4%) con una elevada tasa de mortalidad (19,4%). Predominaron (45,9%) los serotipos sensibles a antibióticos: 8, 3 y 22F. El aumento de CMI para β-lactámicos/resistencia a macrólidos se detectó en los serotipos 19A, 23F, 24F, 6C y 15A. Solo el 10,5% de los adultos candidatos a vacunación tenían una adecuada pauta vacunal antes del episodio y el 40% se debió a serotipos no prevenibles mediante vacunación.

Conclusiones

Los episodios de ENI ocurrieron frecuentemente en adultos de riesgo y se debieron al serotipo 8. Pese a las recomendaciones, las tasas de adherencia a la vacunación fueron muy bajas.